The Radio Times announce the top 20 greatest SciFi programes (excluding Dr Who for some reason) they are:
1 Red Dwarf
2 The X Files
3 Lost
4 Life On Mars
5 Buffy The Vampire Slayer
6 Star Trek: The Next Generation
7 Stargate SG-1
8 Star Trek
9 The Hitch-Hiker's Guide To The Galaxy
10 Quantum Leap
11 Heroes
12 Blake's 7
13 Twin Peaks
14 V
15 Torchwood
16 Babylon 5
17 The Prisoner
18 Battlestar Galactica
19 Thunderbirds
20 Lost In Space.

I can see Heroes jumping up when it airs on BBC2 later this month. As for Battlestar Galactica, surely this must be the old 70's series not the one recently aired on Sky as this too would be a lot higher if seen on terrestrial telly.